Identification, laboratory report, appraisal: three different things

Three different documents get called “getting a stone checked”, and they answer three different questions. Asking the wrong one of them for an answer it does not contain is the most common way people waste a trip to a specialist. Here is what each is, and where a photograph fits.

A visual identification

A visual identification says what the visible evidence supports. Someone, or something, looks at colour and its evenness, transparency, internal features, cut, luster and surface condition, and reports which families the appearance fits and how strongly. It is reasoning from appearance, it names the families it considers and sets aside, and it carries a confidence score because appearance is compatible with more than one answer.

Done from a photograph, this is the weakest of the three and the fastest. It reaches a short list of families rather than a name: “quartz family, amethyst-type purple”, not a species stated as a fact. That is not caution for its own sake. Stones from different families are indistinguishable face up in a picture, and the things that separate them are not visible.

This is what this tool produces, and it is the only one of the three it produces.

A laboratory report

A laboratory report is a measurement document. A gemmological laboratory puts the stone on instruments: refractometer, balance for specific gravity, polariscope, spectroscope, microscope, and more specialised equipment for the harder questions. The stone has to be physically present, the instruments have to be calibrated, and a named person or institution stands behind the result and can be held to it.

A laboratory report is a different kind of object from a visual reading, and no photograph produces one. This tool does not issue one and is not a certificate: it is a written reading of a photograph, produced by software, with its confidence and its limits stated on its face.

An appraisal

An appraisal is a money document. A qualified appraiser examines the piece, establishes what it is, and then states a figure for a stated purpose: insurance replacement, estate division, resale. It rests on identification plus market knowledge plus a purpose, and a figure produced without all three means nothing.

This tool does not price stones and does not appraise them, and no part of its report is a valuation. There are no figures in it at all.

The single clearest statement on this site

No price and no certification comes from a photograph. Not from this tool, not from any other, not from a careful human looking at the same picture. A photograph carries appearance. Money and certification rest on measurements taken with the object in hand and on a person who is accountable for the result, and neither of those can travel through an image file.

For the same reason, a photograph settles nothing about how a stone came to look the way it does, and this tool makes no statement about that either. Those questions belong to a laboratory with the stone on the bench.

Who does which

• Visual identification from a photograph: this tool, in a few seconds, for a short list of families and the limits of the reading.
• Visual identification in person: a qualified gemmologist or a jeweller with gemmological training, with a loupe and a few instruments to hand.
• Laboratory report: a gemmological laboratory.
• Appraisal: a qualified appraiser, often one accredited by a professional body, usually after one of the above has established what the stone is.

The order is not accidental. Each step rests on the one before it, which is why an appraiser asks what the stone is before saying anything else, and why a good visual reading is a useful first step rather than a substitute.

Using the fast step to make the slow one count

A reading from a photograph is useful first because of what it tells you about the next step. It names which families are still in play, which observation would separate them, and therefore what to ask for. Walking into an appointment with “please read the refractive index and tell me whether the needles are angular” is a different conversation from walking in with “what is this”.

So the sequence that wastes the least: photograph the stone properly, read what the picture supports, then take the short list and the specific open question to a qualified person. Read your stone from a photograph to start, and see how to photograph a gemstone for identification so the first step is not wasted on a frame that cannot be read.